Current textIn force on Oct. 7, 2021Source: eCFR
§ 393.19 Hazard warning signals.
Current wording, in the annual edition revised as of Oct. 1, 2005.
49 CFR § 393.19 — Hazard warning signals.. Text in force on October 7, 2021. This wording effective October 1, 2005 to present. Source: eCFR as of October 7, 2021, https://www.ecfr.gov/on/2021-10-07/title-49/section-393.19. Retrieved from FMCSR.com, https://fmcsr.com/reg/393.19?asof=2021-10-07, on October 26, 2026. Unofficial compilation; verify against the official source.
The hazard warning signal operating unit on each commercial motor vehicle shall operate independently of the ignition or equivalent switch, and when activated, cause all turn signals required by § 393.11 to flash simultaneously.
[70 FR 48046, Aug. 15, 2005]
Amendment history
2 distinct wordings on file since Oct. 1, 1996- [70 FR 48046, Aug. 15, 2005]
- Oct. 1, 1996 → Oct. 1, 2005annual editions 1996–2004[53 FR 49397, Dec. 7, 1988]
A new entry appears whenever the regulatory words change between government snapshots. Day-precise from the eCFR (2017 onward); before that, one snapshot per annual CFR edition (revised as of October 1). Bracketed citations are the Federal Register history printed with the section.